Noticeable banging, knocking, or kettling noises from the Triangle Tube water heater during firing.

Safety: Noises often indicate localized boiling. Turn off the unit and allow it to cool before servicing.

• 1. Check system pressure and air: Verify proper system pressure and bleed air from radiators and vents. Air can cause hot spots and noise.
• 2. Verify circulator operation: Ensure the system pump is running and sized correctly. Increase pump speed if adjustable.
• 3. Descale heat exchanger: In hard water areas, scale can form on the heat exchanger, causing kettling. A technician should perform a chemical flush of the primary or DHW heat exchanger using approved descaling solution.
• 4. Check for sludge: Dirty system water can restrict flow. Consider installing or cleaning a dirt separator and flushing the system.
• 5. Monitor after service: After restoring flow and descaling, run the unit and confirm that noises are reduced or eliminated.